Current sensors for electricity metering are often subject to a number of requirements. These may include:                1. Defined geometry of current circuit connections        2. Multiple, adjacent, independent sensors, closely spaced.        3. Excellent immunity to external AC field (either from nearby conductors or from attempts to tamper)        4. Substantially complete immunity to DC magnetic field        5. Low cost        6. Wide dynamic range (typically >=1000:1)        7. Good linearity (typically 0.2%)        